Screw with Waved Thread

ABSTRACT

The present invention is in particular to a plurality of thread portions formed in the second threaded section which forms a wave shape base directrix and spirally surrounds on the shank. Moreover, the upper flanks and the lower flanks extending from said thread portions of said second threaded section also spirally surround as a wave shape base directrix on said shank. Therefore, while in operation, by said thread portions and said upper and lower flanks interlaced and disposed in a waved shape, more portions will increase for cutting; therefore, the cutting efficiency will enhance, the cutting speed will increase, and the torque will reduce. Moreover, the present invention will not loosen or drop out after it is well screwed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a screw design, particularly to a screwwith waved thread.

2. Description of the Related Art

Referring to FIGS. 1 and 2, a conventional screw 1 comprises a head 11,a shank 12 connecting to the head 11, and a plurality of threads 13spirally disposed on the shank 12; wherein, each thread 13 has an upperflank 131 and a lower flank 132 both extending from the shank 12, and anarris 133 disposed between the upper flank 131 and the lower flank 132.Moreover, the threads 13 have a plurality of notches 134 disposedthereon, and a thread portion 135 is formed between any two notches 134.Furthermore, the thread portions 135 are interlaced and are disposed insawtooth shape, and the peaks 136 of the thread portions 135 areinterlaced and are therefore located above or under the waved arris 133.

Due to the thread portions 135 interlaced and disposed in a sawtoothedshape, the area of the conventional screw 1 enabling the object to becut increases. With the assistance of the aforesaid point, while inoperation, the object will be rapidly cut and the screwing speed willenhance. Moreover, when the thread portions 135 in a sawtoothed shapeblocks, the conventional screw 1 can be prevented from loosening ordropping out after it is screwed. However, while in operation, theconventional screw 1 still deserves to be improved, so the presentinvention is invented.

SUMMARY OF THE INVENTION

It is therefore the purpose of this invention to provide a screw withwaved threads with the functions of enhancing the efficiency ofscrewing, reducing the torque of screwing, and preventing itself fromloosening or dropping out.

The screw with waved threads in accordance with the present inventioncomprises a head, a shank connecting to said head, and a thread spirallydisposed on the shank; wherein, said thread has a first threaded sectiondisposed near said head, and a second threaded section disposedoppositely to said first threaded section, and said threaded sectionsconsist of a plurality of interlaced thread portions. Moreover, each ofsaid threaded section has an upper flank and a lower flank bothextending from said shank and a peak located between said upper flankand said lower flank. Furthermore, said peaks of said thread portions ofsaid second threaded section connect to form a wave shape base directrixspirally surrounding on said shank. Still further, said upper flanks andsaid lower flanks also interlaced and disposed in a waved shape.Therefore, there will be more portions for cutting, and the cuttingefficiency will enhance and the torque will reduce. Moreover, afterscrewing, the waved shape design and the blocking of the interlacedthread portions can certainly achieve the functions of preventing fromloosening or dropping out.

The advantages of the present invention over the known prior art willbecome more apparent to those of ordinary skilled in the art uponreading the following descriptions in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a conventional screw;

FIG. 2 is a partial schematic view showing a partial thread of saidconventional screw;

FIG. 3 is a perspective view showing the first preferred embodiment ofthe present invention;

FIG. 4 is a partial schematic view showing the second threaded sectionof said first preferred embodiment;

FIG. 5 is a partial schematic view showing the second threaded sectionof the second preferred embodiment;

FIG. 6 is a partial schematic view showing the second threaded sectionof the third preferred embodiment;

FIG. 7 is a partial schematic view showing the second threaded sectionof the fourth preferred embodiment;

FIG. 8 is a partial schematic view showing the second threaded sectionof the fifth preferred embodiment;

FIG. 9 is a partial schematic view showing the second threaded sectionof the sixth preferred embodiment;

FIG. 10 is a perspective view showing the seventh preferred embodimentof the present invention; and

FIG. 11 is a schematic view showing the eighth preferred embodiment ofthe present invention from its bottom side.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Wherever possible, the same reference numbers are used in the drawingsand the description to refer to the same or like parts.

Referring to FIGS. 3 and 4, the screw with waved thread 2 of the firstpreferred embodiment comprises a head 21, a shank 22 connecting to thehead 21, and a thread 23 spirally disposed on the shank 22; wherein, adrilling member 221 is formed on the shank 22 opposite to the head 21;moreover, the thread 23 has a first threaded section 231 disposed nearthe head 21, and a second threaded section 232 disposed oppositely tothe first threaded section 231, and the two threads 231-232 both consistof a plurality of interlaced thread portions 233; which means a notch234 is formed between each two threaded sections 233, and the depth ofthe notch 234 will be adjusted depending on the different kinds ofobjects that the screw 2 screws. Furthermore, each thread portion 233has an upper flank 235 and a lower flank 236 both extending from theshank 22; a peak 237 which located between the upper flank 235 and thelower flank 236 and is a cutting point, spirally surrounds on the secondthreaded section 232 of the shank 22 and forms a wave shape basedirectrix α; besides, said upper and lower flanks 235-236 of the threadportions 233 also spirally surround as the wave shape base directrix αon the shank. Certainly, the distance between the peaks 237 of each twoadjacent thread portions 233, which means the width of the notch 234,can be disposed in different width, and in this preferred embodimentthey are shown in the same width.

Referring to FIG. 4, while in operation, first the second threadedsection 232 is used to screw, which means the threaded section 232 areinterlaced and are spirally disposed on the shank 22 in a waved shape,and the second threaded section 232 has a plurality of portions forcutting and increases the effect of cutting while in operation, thesecond threaded section 232 therefore can screw into the object in arapid and labor-saving way, and the torque also decreases. Finally, thefirst threaded section 231 is now used to screw. In this moment, thefirst threaded section 231 also makes use of the interlaced threadportions 233 to have a better cutting effect on screwing until the screw2 is actually screwed. Moreover, while the screw 2 is screwed, theinterlaced thread portions 233 of the first threaded section 231 and thesecond threaded section 232 can increase the effect of preventing fromloosening and dropping out.

Referring to FIG. 5, the drawing shows the second preferred embodimentof the present invention. The main difference between this preferredembodiment and the first preferred embodiment is that the threadportions 235 of the second threaded section 232 are interlaced in anon-symmetry way to be disposed in one side of the wave shape basedirectrix α. As the drawing shows, three thread portions 233 areconsidered as a group disposed in one side. It can also be theembodiment as FIG. 6 shows, three thread portions 233 are considered asa group disposed in one side, and another group of thread portions 233are disposed in the other side interlaced with the aforesaid group ofthread portions 233. No matter in what way the thread portions 233 aredisposed, they are all used to increase the screwing ability of thesecond threaded section 232.

Referring to FIG. 7, the drawing shows the fourth preferred embodimentof the present invention and most of its factors are the same as thescrew 2 of the first preferred embodiment. To be more specific, thepeaks 237 of the thread portions 233 of the second threaded section 232form a cutting line which forms an included angle with the wave shapebase directrix α Certainly, the peak 237 can also be a cutting face asFIG. 8 shows. However, no matter the peaks 237 of the thread portions233 are designed as the cutting line or the cutting face, they bothincrease the cutting ability in screwing.

Referring to FIG. 9, the drawing shows the sixth preferred embodiment ofthe present invention and most of its factors are the same as the screw2 of the first preferred embodiment. To be more specific, a powerreceiving face 239 is formed on the side of the peak 237; moreover, thepeak 237 in this embodiment is a cutting point in order to allow thethread portions 233 to be able to suffer more power.

Referring to FIG. 10, the drawing shows the seventh preferred embodimentof the present invention. In this embodiment, although the threadportions 233 can be designed as the type of the thread portions 233 inthe second preferred embodiment to the sixth preferred embodiment, thetype of the first preferred embodiment is used here. To be morespecific, a plurality of wave-shaped threads 25 are disposed between thefirst threaded section 231 and the head 21 to lead to the screw 2fastening to the object from the second threaded section 232 to thefirst threaded section 231 orderly, and further accompanying with thethreads 25 disposed in wave-shaped, said threads 25 hence can be wellengaged with the object (not shown in the drawing). Therefore, thepresent invention will not loosen or drop out after it is well screwed.

Referring to FIG. 11, the drawing shows the eighth preferred embodimentof the present invention and most of its factors are the same as thescrew 2 of the first preferred embodiment. To be more specific, theshank 22 and the threads 23 form a polygon, and they are shown as atriangular shape in this drawing. Therefore, while in operation, exceptthe functions of increasing the cutting efficiency, reducing the torqueand preventing from loosening or dropping out, further accompanying theshank 22 and the threads 23 relying on the point of the triangle to cutthe object (not shown in the drawing), the friction appearing fromscrewing will hugely reduce and achieve the effect of rapid screwing.

To sum up, the present invention is in particular to a plurality of thethread portions formed in the second threaded section which forms a waveshape base directrix and spirally surrounds on the shank; wherein, theupper and lower flank extended from the thread portions also spirallysurround as the wave shape base directrix on the shank. Therefore, theportions for cutting increase, and the screw has the benefit ofenhancing the efficiency and speed of cutting and reducing the torque.Still further, with the thread portions interlaced and in waved shape toblock, the present invention will not loosen or drop out after it iswell screwed.

While we have shown and described the embodiment in accordance with thepresent invention, it should be clear to those skilled in the art thatfurther embodiments may be made without departing from the scope of thepresent invention.

1. A screw with waved thread comprising: a head; a shank connecting tosaid head with a drilling member formed opposite to the said head; and athread having a first threaded section disposed near said head, and asecond threaded section disposed oppositely to said first threadedsection; wherein, said threaded sections consist of a plurality ofinterlaced thread portions, and each said thread portion has an upperflank and a lower flank both extending from said shank and a peaklocated between said upper flank and said lower flank; moreover, saidpeaks of said thread portions of said second threaded section connect toform a wave shape base directrix surrounding on said shank; furthermore,said upper flanks and said lower flanks from said thread portions ofsaid second threaded section also form a wave shape base directrixbetween them and said shank, and said wave shape base directrix spirallysurrounds on said shank.
 2. The screw as claimed in claim 1, wherein,the distance of the peaks of each two adjacent thread sections of saidsecond threaded section is not all in the same width.
 3. The screw asclaimed in claim 1, wherein, at least the peaks of any two adjacentthread sections are disposed on one side of said wave shape basedirectrix.
 4. The screw as claimed in claim 1, wherein, said peaks ofsaid threaded sections form a cutting line.
 5. The screw as claimed inclaim 4, wherein, said cutting line and said wave shape base directrixforms an included angle.
 6. The screw as claimed in claim 1, wherein,the peak of each said thread portion forms a cutting face.
 7. The screwas claimed in claim 1, wherein, a power receiving face is formed on theside of said peak.
 8. The screw as claimed in claim 1, wherein aplurality of wave-shaped threads are disposed between said firstthreaded section and said head.
 9. The screw as claimed in claim 1,wherein, said shank forms a polygonal shape.
 10. The screw as claimed inclaim 1, wherein, any of said thread section forms a polygonal shape.